<?php
    // Simple browser detection  
    $is_lynx = $is_gecko = $is_winIE = $is_macIE = $is_opera = $is_NS4 = $is_safari = $is_chrome = $is_iphone = false;  
       
    if ( isset($_SERVER['HTTP_USER_AGENT']) ) {  
        if ( strpos($_SERVER['HTTP_USER_AGENT'], 'Lynx') !== false ) {  
            $is_lynx = true;  
        } elseif ( stripos($_SERVER['HTTP_USER_AGENT'], 'chrome') !== false ) {  
            if ( stripos( $_SERVER['HTTP_USER_AGENT'], 'chromeframe' ) !== false ) {  
                $is_admin = is_admin();  
                /** 
                 * Filter whether Google Chrome Frame should be used, if available. 
                 * 
                 * @since 3.2.0 
                 * 
                 * @param bool $is_admin Whether to use the Google Chrome Frame. Default is the value of is_admin(). 
                 */  
                if ( $is_chrome = apply_filters( 'use_google_chrome_frame', $is_admin ) )  
                    header( 'X-UA-Compatible: chrome=1' );  
                $is_winIE = ! $is_chrome;  
            } else {  
                $is_chrome = true;  
            }  
        } elseif ( stripos($_SERVER['HTTP_USER_AGENT'], 'safari') !== false ) {  
            $is_safari = true;  
        } elseif ( ( strpos($_SERVER['HTTP_USER_AGENT'], 'MSIE') !== false || strpos($_SERVER['HTTP_USER_AGENT'], 'Trident') !== false ) && strpos($_SERVER['HTTP_USER_AGENT'], 'Win') !== false ) {  
            $is_winIE = true;  
        } elseif ( strpos($_SERVER['HTTP_USER_AGENT'], 'MSIE') !== false && strpos($_SERVER['HTTP_USER_AGENT'], 'Mac') !== false ) {  
            $is_macIE = true;  
        } elseif ( strpos($_SERVER['HTTP_USER_AGENT'], 'Gecko') !== false ) {  
            $is_gecko = true;  
        } elseif ( strpos($_SERVER['HTTP_USER_AGENT'], 'Opera') !== false ) {  
            $is_opera = true;  
        } elseif ( strpos($_SERVER['HTTP_USER_AGENT'], 'Nav') !== false && strpos($_SERVER['HTTP_USER_AGENT'], 'Mozilla/4.') !== false ) {  
            $is_NS4 = true;  
        }  
    }  
       
    if ( $is_safari && stripos($_SERVER['HTTP_USER_AGENT'], 'mobile') !== false )  
        $is_iphone = true;  
       
    $is_IE = ( $is_macIE || $is_winIE );  
       
    // Server detection  
       
    /** 
     * Whether the server software is Apache or something else 
     * @global bool $is_apache 
     */  
    $is_apache = (strpos($_SERVER['SERVER_SOFTWARE'], 'Apache') !== false || strpos($_SERVER['SERVER_SOFTWARE'], 'LiteSpeed') !== false);  
       
    /** 
     * Whether the server software is Nginx or something else 
     * @global bool $is_nginx 
     */  
    $is_nginx = (strpos($_SERVER['SERVER_SOFTWARE'], 'nginx') !== false);  
       
    /** 
     * Whether the server software is IIS or something else 
     * @global bool $is_IIS 
     */  
    $is_IIS = !$is_apache && (strpos($_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS') !== false || strpos($_SERVER['SERVER_SOFTWARE'], 'ExpressionDevServer') !== false);  
       
    /** 
     * Whether the server software is IIS 7.X or greater 
     * @global bool $is_iis7 
     */  
    $is_iis7 = $is_IIS && intval( substr( $_SERVER['SERVER_SOFTWARE'], strpos( $_SERVER['SERVER_SOFTWARE'], 'Microsoft-IIS/' ) + 14 ) ) >= 7;  
       
    /** 
     * Test if the current browser runs on a mobile device (smart phone, tablet, etc.) 
     * 
     * @return bool true|false 
     */  
    function wp_is_mobile() {  
        static $is_mobile;  
       
        if ( isset($is_mobile) )  
            return $is_mobile;  
       
        if ( empty($_SERVER['HTTP_USER_AGENT']) ) {  
            $is_mobile = false;  
        } elseif ( strpos($_SERVER['HTTP_USER_AGENT'], 'Mobile') !== false // many mobile devices (all iPhone, iPad, etc.)  
            || strpos($_SERVER['HTTP_USER_AGENT'], 'Android') !== false  
            || strpos($_SERVER['HTTP_USER_AGENT'], 'Silk/') !== false  
            || strpos($_SERVER['HTTP_USER_AGENT'], 'Kindle') !== false  
            || strpos($_SERVER['HTTP_USER_AGENT'], 'BlackBerry') !== false  
            || strpos($_SERVER['HTTP_USER_AGENT'], 'Opera Mini') !== false  
            || strpos($_SERVER['HTTP_USER_AGENT'], 'Opera Mobi') !== false ) {  
                $is_mobile = true;  
        } else {  
            $is_mobile = false;  
        }  
       
        return $is_mobile;  
    }  